Modulation of SK channel trafficking by beta adrenoceptors enhances excitatory synaptic transmission and plasticity in the amygdala.
Emotionally arousing events are particularly well remembered. This effect is known to result from the release of stress hormones and activation of beta adrenoceptors in the amygdala. However, the underlying cellular mechanisms are not understood. Small conductance calcium-activated potassium (SK) channels are present at glutamatergic synapses where they limit synaptic transmission and plasticity. Here, we show that beta adrenoceptor activation regulates synaptic SK channels in lateral amygdala pyramidal neurons, through activation of protein kinase A. We show that SK channels are constitutively recycled from the postsynaptic membrane and that activation of beta adrenoceptors removes SK channels from excitatory synapses. This results in enhanced synaptic transmission and plasticity. Our findings demonstrate a novel mechanism by which beta adrenoceptors control synaptic transmission and plasticity, through regulation of SK channel trafficking, and suggest that modulation of synaptic SK channels may contribute to beta adrenoceptor-mediated potentiation of emotional memories.
Faber
E S Louise
ES
Queensland Brain Institute and School of Biomedical Sciences, The University of Queensland, Brisbane QLD 4072, Australia.
Delaney
Andrew J
AJ
Power
John M
JM
Sedlak
Petra L
PL
Crane
James W
JW
Sah
Pankaj
P
D018663:Adrenergic Agents / Q000494:pharmacology; D000679:Amygdala / Q000166:cytology*; D000818:Animals; D000831:Animals, Newborn; D001030:Apamin / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004558:Electric Stimulation / Q000379:methods; D004705:Endocytosis / Q000187:drug effects; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D009924:Organ Culture Techniques / Q000379:methods; D018408:Patch-Clamp Techniques / Q000379:methods; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism*; D014162:Transfection
D018663:Adrenergic Agents; D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D011943:Receptors, Adrenergic, beta; D051640:Small-Conductance Calcium-Activated Potassium Channels; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D001030:Apamin; D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid